S.M.A.R.T.

S.M.A.R.T. (Self-Monitoring, Analysis, and Reporting Technology) is a supplementary component built into many modern storage devices through which devices monitor, store, and analyze the health of their operation. Statistics are collected (temperature, number of reallocated sectors, seek errors...) which software can use to measure the health of a device, predict possible device failure, and provide notifications on unsafe values.

Smartmontools

The smartmontools package contains two utility programs for analyzing and monitoring storage devices: smartctl and smartd. Install the smartmontools package to use these tools.

SMART support must be available and enabled on each storage device to effectively use these tools. You can use #smartctl to check for and enable SMART support. That done, you can manually #Run a test and #View test results, or you can use #smartd to automatically run tests and email notifications.

smartctl

smartctl is a command-line tool that "controls the Self-Monitoring, Analysis and Reporting Technology (SMART) system built into most ATA/SATA and SCSI/SAS hard drives and solid-state drives."

The -i/--info option prints a variety of information about a device, including whether SMART is available and enabled:

View test results

You can view a device's overall health with the -H flag. "If the device reports failing health status, this means either that the device has already failed, or that it is predicting its own failure within the next 24 hours. If this happens […] get your data off the disk and to someplace safe as soon as you can."

# smartctl -H /dev/<device>

You can also view a list of recent test results and detailed information about a device:

# smartctl -l selftest /dev/<device>
# smartctl -a /dev/<device>

smartd

The smartd daemon monitors SMART statuses and emits notifications when something goes wrong. It can be managed with systemd and configured using the /etc/smartd.conf configuration file. The configuration file syntax is esoteric, and this wiki page provides only a quick reference. For more complete information, read the examples and comments within the configuration file, or read smartd.conf(5).

daemon management

To start the daemon, check its status, make it auto-start on system boot and read recent log file entries, simply start/enable the smartd.service systemd unit.

Define the devices to monitor

To monitor for all possible SMART errors on all disks, the following setting must be added in the configuration file.

/etc/smartd.conf

DEVICESCAN -a

Note this is the default smartd configuration and the -a parameter, which is the default parameter, may be omitted.

To monitor for all possible SMART errors on /dev/sda and /dev/sdb, and ignore all other devices:

/etc/smartd.conf

/dev/sda -a
/dev/sdb -a

To monitor for all possible SMART errors on externally connected disks (USB-backup disks spring to mind) it is prudent to tell smartd the UUID of the device since the /dev/sdX of the drive might change during a reboot.

First, you will have to get the UUID of the disk to monitor: ls -lah /dev/disk/by-uuid/ now look for the disk you want to Monitor

I know that my USB disk attached to /dev/sde during boot. Now to tell smartd to monitor that disk simply use the /dev/disk/by-uuid/ path.

/etc/smartd.conf

/dev/disk/by-uuid/820cdd8a-866a-444d-833c-1edb0f4becac -a

Now your USB disk will be monitored even if the /dev/sdX path changes during reboot.

Notifying potential problems

To have an email sent when a failure or new error occurs, use the -m option:

/etc/smartd.conf

DEVICESCAN -m address@domain.com

To be able to send the email externally (i.e. not to the root mail account) a MTA (Mail Transport Agent) or a MUA (Mail User Agent) will need to be installed and configured. Common MTAs are Msmtp and SSMTP. Common MTUs are sendmail and Postfix. It is enough to simply configure S-nail if you do not want anything else, but you will need to follow these instructions.

The -M test option causes a test email to be sent each time the smartd daemon starts:

/etc/smartd.conf

DEVICESCAN -m address@domain.com -M test

Emails can take quite a while to be delivered. To make sure you are warned immediately if your hard drive fails, you may also define a script to be executed in addition to the email sending:

/etc/smartd.conf

DEVICESCAN -m address@domain.com -M exec /usr/local/bin/smartdnotify

To send an email and a system notification, put something like this into /usr/local/bin/smartdnotify:

If you are running a desktop environment, you might also prefer having a popup to appear on your desktop. In this case, you can use this script (replace X_user and X_userid with the user and userid running X respectively) :

Power management

If you use a computer under control of power management, you should instruct smartd how to handle disks in low power mode. Usually, in response to SMART commands issued by smartd, the disk platters are spun up. So if this option is not used, then a disk which is in a low-power mode may be spun up and put into a higher-power mode when it is periodically polled by smartd.

As an alternative you can user -i option of smartd. It controls how often smartd spins the disks up to check their status. Default is 30 minutes. To change it create and edit /etc/default/smartmontools.

Schedule self-tests

smartd can tell disks to perform self-tests on a schedule. The following /etc/smartd.conf configuration will start a short self-test every day between 2-3am, and an extended self test weekly on Saturdays between 3-4am:

/etc/smartd.conf

DEVICESCAN -s (S/../.././02|L/../../6/03)

Alert on temperature changes

smartd can track disk temperatures and alert if they rise too quickly or hit a high limit. The following will log changes of 4 degrees or more, log when temp reaches 35 degrees, and log/email a warning when temp reaches 40:

/etc/smartd.conf

DEVICESCAN -W 4,35,40

Tip: You can determine the current disk temperature with the command smartctl -A /dev/<device> | grep Temperature_Celsius

Tip: If you have some disks that run a lot hotter/cooler than others, remove DEVICESCAN and define a separate configuration for each device with appropriate temperature settings.

Complete smartd.conf example

Putting together all of the above gives the following example configuration:

DEVICESCAN smartd scans for disks and monitors all it finds

-a monitor all attributes

-o on enable automatic offline data collection

-S on enable automatic attribute autosave

-n standby,q do not check if disk is in standby, and suppress log message to that effect so as not to cause a write to disk